well - bonnetheads are also kind of picky feeders - and really best left to expert shark keeper.
Still robn - if you get the 750 gallon tank (10' x 4' x 2.5') - you would really open your options up, as to the types & amount of sharks that you could keep.
You could go with bamboos, epaulettes, carol catsharks, small wobbies(like Japanese), or the Horn shark. And you could actually have several sharks.
Your could easily keep a couple of bamboos, an epaulette, & and a coral catshark all together in a 750.
Or maybe a pair of japanese wobbies, or a pair of horn sharks - if you were thinking about breeding your sharks.
Actually if you stick with bamboos & eppies - you could do this - get a pair(male & female) of bamboos(which ever species - you want), as well as a pair of epaulettes, then breed both species, together in the same tank.
just a few thoughts.